Graphical user interface for a display screen or portion thereof



The single FIGURE is a front view of a graphical user interface for a display screen or portion thereof showing my new design.

The broken line showing of the display screen or portion thereof is not part of the claimed design.

The AT&T trademark in the upper left corner of the Figure is a registered trademark of AT&T Intellectual Property II, L.P. The Genius trademark in the center of the Figure is a registered trademark of Apple Inc. Trademarks are the property of their respective owners. 

The ornamental design for a graphical user interface for a display screen or portion thereof, as shown and described. 